Their policies are strict. Be sure to read through Amazon’s affiliate program policies very carefully. Any violation of their policies is grounds for account suspension--something which could be devastating if you build an entire website or store around affiliate links. Amazon has also been known to suspend accounts without any prior notice, so tread carefully.
Once you’ve set up your account, do note that Amazon requires you to use product links and generate income from at least three of them within 180 days. If you fail to do so within that time, they will close your account. If you are able to satisfy that requirement, Amazon will review your account as well as your usage of affiliate links once the first sale is complete.